Stair construction.



-N mm Aw HR 1 M S APPLICATION FILED JAN. 27

Patented Apr. 7, 1914.

STAIR CONSTRUCTION.

Specification of Letters Patent.

Patented Apr. 7, 1914.

Application filed January 27, 1913. Serial No. 744,302.

To all whomit may concern Be it known that l, FREDERICK IIARTMANN, aresident of Cincinnati, Hamilton county, State of Ohio, have inventedcertain new and useful Improvements in Stair Construction; and I dodeclare the following to be a clear, full, and exact description of myinvention, attention being called to the drawing, which accompanies thisapplication and forms a part thereof.

This invention relates to improvements in stair-construction where thematerials used are chiefly metal and concrete or similar sub stances.

Metal, preferably iron inkinds best suited for the purpose, is used tomake up the skeleton of the structure and is relied upon for thestrength and stability of the same. Concrete, plaster and similarequivalent materials are used to cover this metal skeleton, to protectit against fire and to permit application of ornamental effects.

The invention consists of a construction whereby the various parts ofthe structure and the different materials thereof are connected andjoined in a practical and substantial manner, one of the features beingthe provision of the steps, which are completed each as a unit whichembodies riser and tread, permitting ready connection in position, aswell as independent removal of any step for replacement and repair.

In the following specification and particularly pointed out in theclaims at the end thereof, will be found a full description of myinvention, together with its manner of use, parts and construction,which latter is also illustrated in the accompanying drawing, in which aFigure 1, shows in sideelevation a flight of steps. Fig. 2, is anenlarged vertical cross-section of a portion thereof. Fig. 3, is avertical section taken on line 3-3 of Fig. 2. Fig. i, is a top-view ofone of the steps detached and with parts broken away. Fig. 5, is aperspective view of a portion of such a step viewed from the rear andunderside.

Letter A in the drawing, indicates one of the side-frames or horseswhich serve for supporting the steps. These horses also known asstringers are preferably made of steel and stiffened by means of anglesaa, secured to their outer sides and at their parallel edges. They areprotected against fire by a shell 8, of concrete or plaster whichpermits also application of ornamental effects as shown in Fig. 1, Thisshell is spaced from the horse, so as to produce a dead air space asshown at 9, which increases the security against fire. It is supportedupon a backing 11, formed preferably of metallic lath, stretched betweenangles w-a and held' in place by the lugs 12.

The steps consist of the tread-portion B and of the riser G, the formermade of concrete and the latter preferably of cast-iron. The concrete iscarried by rods Z) supported in opposite cheek-plates13, connected "tothe ends of riser C by means of flanges 14. The ends of these rods arepreferably riveted into these cheek-plates and serve to stiffen thestep-structure. The concrete at the free edge of the tread is protectedby a nosing 15 which forms part of the riser and is rear wardly open topermit the concrete to key in. The concreteportion is formed in positionon the riser and on rods 6 in suitable molds. The rear edge of the treadis fitted against the front side of the riser of the step above and upona flange 16 which projects from the face of said riser, but withoutconnection to said flange.

It will be observed from inspection of Figs. 4: and 5, that each step iscomplete and forms a self-contained unit, embodying a tread and a riserand ready for connection as a whole to the stair-horses or stringers.For such purpose angles 17 are provided on the inside of the horseswhich form oppositel-edges, adapted to receive the ends of the steps andto support them. By preference, the lower edges of the cheek-plates arefitted to rest upon these ledges.

Screws or bolts 18 are applied whereby the steps at the cheek-plates 13are connected to the inner side of the stringers. Each step isindependently connected and there is no connection between adjoiningsteps. A soffitmay be formed on the underside of the steps and betweenthe horses by means of a coat of concrete or plaster 19 formed uponmetallic lath 20. This latter is supported on lugs 21 by means of wireloops 22, said lugs being provided on the under-side of the steps. Bypreference they project from the inner side of the risers.

Having described my invention, I claim as new:

1. In stair-construction, the combination of the steps and metallicside-frames on which they are supported, said side-frames beingstiffened by angles on their outer side,

attached to the parallel edges of these sides, and a shell of concreteprovided on the outer side of these frames and between these angles andspaced from these frames.

2. In stair-construction, the combination of side-frames, independentlyformed steps each consisting of a. metallic riser, rear- Wardlyprojecting cheek-plates connected to the ends of these risers, rodsprovided between these plates and connected thereto, concrete treadsformed on these rods and on the upper edge of the risers, and meansengaging the cheek-plates for securing the steps to the side-framesabove mentioned.

3. In stair-construction, the combination of sidefra1nes, independentlyformed steps, consisting of metallic risers provided at their upperedges with a forwardly projecting and rearwardly open'nosing and attheir lower edges with a forwardly projecting flange, cheek-platesprojecting rearwardly from the ends of the risers, rods extendingbetween these plates. and connected thereto, concrete treads formed onthese rods and joined tothe nosing at the upper edge of the risers andfitted to extend over the flange on the lower edge of the riser ofthestep adjoining and means engaging the cheek-plates for supportingthese steps on theside-frames above mentioned.

In testimony whereofil hereunto aflix my signature in the presence oftwo witnesses. FREDERICK HARTMANN. lVitnesses: V

C. SPENGEL,1

T. LE BEAU;

Copies of this patent may be obtained for five cents each, by addressingthe Commissioner of Patents,

Washington, D. C. V i

